rate of change, how can it be included in emission metrics?
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Rate of change, how can it be included in emission metrics?. Terje Berntsen CICERO/University of Oslo, Norway. Workshop on common metrics, Bonn, April 2012. Rate of Change and the UNFCCC. ARTICLE 2: OBJECTIVE - PowerPoint PPT PresentationTRANSCRIPT
Rate of change, how can it be included in emission metrics?
Terje Berntsen
CICERO/University of Oslo, Norway
Workshop on common metrics, Bonn, April 2012
Rate of Change and the UNFCCC
ARTICLE 2:OBJECTIVE
The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.
Rate of Change and the UNFCCC
ARTICLE 2:OBJECTIVE
The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.
Point of departure:
Keep to the cost-effective framework indicated in UNFCCC article 2
• Use global mean temperature as indicator
• Keep the constraint of a long-term stabilization target (i.e. the 2°C target)
• Add a constraint on rate of temperature change
Basic question (all metrics): When are the constraint(s) binding? Time horizon
Basic question (all metrics): When are the constraint(s) binding? Time horizon
tL
Basic question (all metrics): When are the constraint(s) binding? Time horizon
Rate limit 0.02K/yr
tR
Basic question (all metrics): When are the constraint(s) binding? Time horizon
Similar approach as Manne & Richels (Nature, 2001)
Numerical examples based on pulse AGTP (ΔT(t))
Construction of a rate and level based metric MR&L
Rate term
Level term
tR=2040tL=2070
Construction of a rate and level based metric MR&L
Rate term
Level term
Combined and relative to CO2
f = 0.5 for t<tR and f=0 for t> tR
MR&L for methane
GWP100
Manne & Richels, 2001
MR&L also for BC (Direct effect)
Summary
• A purely physical metric including both rate and level based constraint can be constructed
• Requires additional value judgments• E.g. weighting factor rate vs. Level• Rate constraint
• MR&L ≤ GWP100 in the early phase for SLCFs
• Alternatively• Consider rate of change as a independent
environmental issue • Regulate SLCFs in a separate basket, could
use MR as metric for this basket